nader is liberal, a mix of green and reform party. he ran in 2000 for pres. for the green party, but in 2004 lost the nomination to cobb. (there's some controversy about that, he won the popular green vote, but they employ a electoral system. so cobb, (being more popular in california) got the win. in a few states where nader got on the ballot, he's listed as a reform candidate, but is largely viewed as an independant. I find it hysterically ironic that one of the issues in the green platform is electoral system reform. to be fair, most facets of the green and reform parties aren't mutually exclusive, perhaps seeking endorsements from both wasn't such a bad idea... even though he wants to crack the two-party system with a third alternative instead of a third and fourth.
for more info:
http://www.nader.org/http://greensfornader.net/http://www.gp.org/http://www.reformparty.org/